Traveling crane



TRAVELING CRANEv Oct. 25, 1932.

Filed June 6. 1929 4 Sheets-Sheet l Oct. 25, 1932. B. F. FITCH TRAVELING CRANE Filed June 6, 1929 4 Sheets-Sheet 2 gwuento'o $79M Oct. 25, 1932. B. F. FITCH TRAVELING'CRANE Filed June 6, 1929 4 Sheets-Sheet 5 Fen-" Oct. '25, 1932. B, F HT H 1,884,641

' TRAVELING CRANE Filed June 6. 1929 4 sheets-sheet 4 Patented Oct. 25, 1932 UNITED STATES PATENT oFscE BENJAMINF. FITCH, OF GREENWIGH, CONNECTICUT, ASSIGNOR TO MOTGR TERMI NALS COMPANY, OF WILMINGTON, DELAWARE, A CORPORATIOII OF DELA'WARE V TRAVELING CRANE Application filed June 6, 1929. Serial No. 368,958.

' The obj ect of this invention is to provide an eflicient mechanism embodied in a hoist or a traveling crane for raising and-lowering a pair of loads so that one, to a greater or lessextent, counterbalanc'es the other. More particularly, my hoist mechanism is designed for manipulating demountable automobile bodies. It isadapted for instance, to pick up a loaded body from an automobile truck and at the same time lower another body carried'by the hoist onto a suitable truck or platform. M V

The invention is most valuable when em-' bodied in a traveling crane at a suitable transfer station, in which case, it may, for instance,

pick up a loaded body from a platform, and carry it"to a position over, a truck runway; whereupon the other portion of the hoisting mechanism is attached to ademountable body so on a-truck in such runway and that body raised as the former body is lowered; then by trolleying the hoist, the body from the platform may be deposited on the truck in place of the one just removed therefrom.

" ,5 It will be seen therefore, that this invention enables very rapid handling of demountable bodies between automobile trucks and a suitable platform or other supporting means to and from which they may. be transferred. In carrying out the invention, I provide a hoist or crane frame having a suitably driven rotatable screw engaging a traveling nut.

The cablesvlead from this nut in opposite directions around suitable sheaves and then depend-to their respective loads. Thus, the rotation of the screwby shifting the nut will lower one cable and raise the other, while the loads on the respective cables counteract each other. The invention is'hereafter more fully'explained in connection with the drawings and its essentialnovel features set out in the claims.

In the drawings, Fig. 1 is a plan of a sim- I ple embodiment of my invention, partly broken away; Fig. 2 is a vertical transverse section partly broken away, the plane of the section being indicated by the line 2-2 on Fig. 1; Fig. 3 is an end view of the hoist apparatus, shown in conjunction with automobile trucks having removable bodies in a truck runway beneath'the hoist; Fig. 4 is a sectional plan of a portion of thehoist adjacent the driving end of the screw; Fig. 5 is a similar view adjacent the other end of the screw Fig. 6 is a vertical cross section through certain of the hoist sheaves adjacent the driving end of the screw; Fig. 7 is a vertical cross section through the bearing for the driving screw, the plane of'the section being indicated by the lines 7 7 on Fig. h

As shown in Figs. 1, 2 and 3, 10 and 11 indicate a pair of parallel supporting rails for the hoist embodied asa traveling crane. These rails are supported in any suitable manner, as by posts or brackets. They extend parallel with each other, preferably at a height above the platform (indicated at 20 in Fig. 8) somewhat more than twice the height of a demountable automobile'body with which the device is intended to operate.

21 in Fig. 3 indicates a truck runway along the end of the platform 20 over which the crane rails 10 extend. This view shows a pair of automobile trucks A and A1 standing in this runway. 13 and B1 inoicate demountable bodies adapted to be carried by such trucks; as shown, one body is in position resting on the truck and about to be raised, the other body being in position above the truck and about to be lowered thereon.

The frame of my traveling crane is shown as comprising a pair of parallel longitudinal beams 30 at one side, a corresponding pair of beams 31 at the other side and various cross braces at 32 to 39 inclusive. Between the two beams 30 are mounted suitably flanged wheels l-O resting on the track rails 10. Similar wheels 41 are mounted between the beams 31-31 and engage the track rails 11.

Suitable power means is preferably provided for rotating one of the wheels 4.0 and 41 on each side to move the hoist frame along the trackway, in other words, trolley the hoist. To this end I have shown a pair of spur gears 42' and 43 mounted on the Wheels 10 and 41 (nearest the bottom of Fig. 1) meshing with pinions 44: and 45 on a through shaft 46 which carries a worm wheel 47. Meshing with this worm wheel is a these hearings suitable heads 53 and 54either of which is adapted to cooperate with an abutment when the screw is pulled in the direction from the head, but to be idle when the screw is shoved in the direction toward the head. Preferably, suitable rolling mem-' bers are rovided between the respective heads and the outer sides of a pair of longitudinal frame beams 60 and 61 which carry the cylindrical bearings 51 and 52. Thus, I have shown at one end a set of rollers 55 and the other end rollers 56 carried by suitable cages 57 and bearing against resistance plates 58. On the inner side of the bearings, suitable overhanging sleeves 59 holds the beari in place.

On e screw is a nut which has wings 71 extending between the flanges of a pair of parallel transverse beams 63 and 64 which serve to guide the nut and prevent its rotation. Accordingly, as the screw is rotated, the nut is caused to travel, in either direction desired, according to the direction of rotation of the screw.

Two sets of cables lead from opposite ends of the nut 7 0 and pass downwardly to the respective loads. As the hoist is designed primarily for raising automobile bodies, to be engaged'at four points constituting the four corners of a rectangle, each set of cables conipi'ises four cables which extend first parallel with the screw and then laterally and eventually pass downwardly over four sheaves to the load.

It will be seen that four cables 80, 81, 82 and 83 pass from the nut 70 parallel with the screw; then two of these cables, 81 and 83, one directly over the other, pass first around sheaves and 91, thence the cable 81 continues for a considerable distance parallel with the screw and passes downwardly over a sheave 92 while the cable 83 after leaving the sheave 91, passes parallel with the screw for a short distance only and then depends over a sheave 93. This provides two depending cables for one side of the load. Similar- 3; the other two cables 80 and 82 pass around eaves 94 and 95; thence laterally to a point near the extreme end of the hoist; thence around sheaves 96 and 97 then the upper cable 80 leads well toward the other side of the hoist where it depends about the sheave 98, while the cable 82 depends about the sheave 99. This provides two depending members for the other side of the demountable body. Accordingly the travel of the nut in the direction to pull on the four cables 80 to 83 is adapted to raise the body to which the four ends of these cables may be attached.

In a. similar manner cables 100, 102, pass about sheaves 111 and 112, thence transversely parallel with the screw and pass downwardly about sheaves 113 and 114, and the cables 101 and 103 pass first about sheaves 115 and 116, thence about sheaves 118 and 119 and thence pass forwardly and depend over sheaves 120 and 121 to the load. Thus there are four depending cables on this side of the hoist adapted to engage ademountable body. Each of the depending cables is provided at its end with suitable means for engaging the demountable body. I have shown conventionally, an eye at the end of each cable adaptedto engage a hook 131 carried at the cave of the demountable body. However,

other means of attaching the cable to the body mav be employed if desired.

It will be seen that when the two sets of four cables each are attached to the two bodies, as shown in Fig. 3, the rotation of the screw may raise one body and simultaneously lower the other, while each body counterbalances the other to the extent of the weight of the lightest of the two bodies.

To rotate the screw, I have shown a spur gear attached to the screw near one end. A train of gearing 151, which may have reduction if desired, connects the spur gear 150 with the pinion 152 on the armature shaft of a motor 153. Accordingly, by reversing and controllin this motor, the loads may be raised or owered as desired. The pitch of the screw issuch that any thrust on the nut cannot turn the screw, and hence the device is self locking with the bodies in any position.

It is important that the reaction of the screw on the hoist frame be one of tension and not compressiombecause the screw has considerable length and must not be distorted by the stress put upon it; moreover it is desirable to maintain the hoist frame at the minimum of depth to allow its installation where there is little head room; hence it is desirable to have the screw of a small diameas practicable to carry the load. To effect this I provide the peculiar arrangement of bearings shown; that is, at either end of the screw, a plain c lindrical bearing for supporting the weig t of the screw itself, and a thrust bearing to receive a pull of the screw uponthe bearing, while at the other end the screw is free to push without resistance.

In use the heavier of the two bodies being sup orted by the cables will pull the nut and wit 1 it the screw, so that the reaction is taken on the bearing at the pulled end of the screw, the screw at the other end simply rotating freely in its cylindrical bearing with its thrust bearin out-of action. If the body which was ho ding the screw in this position is deposited on the truck or platform, thus Ill relieving the stress on the cables, the weight of the other body will transfer the thrust to the hearing at the other end of the screw, but in neither case will any portion of the screw be under compression. If the two loads e2; actly balance, there will be no tension on the screw in either direction. The change of tension from one direction to the other may cause a slight longitudinal travel of the screw, taking up the bearing clearance at one end and giving clearance, at the other, but this does not interfere in any manner with the driving of the screw, as the spur gear 150 may simply slide if necessary on the meshing gear of the train 151.

It will be seen that I have provided a simple. traveling crane adapted for hoisting and transporting two automobile bodies, elevating one and lowering the other as desired for efficient operation; that the weight of one body tends to counterbalance the other, thus reducing the load on the driving mechanism; that the mechanism is self locking and supports the loads wherever the power mechanism may have left them. By arranging the screw so that it is always under tension, I greatly reduce the diameter necessary for the screw, and thereby reduce the size of the cooperating parts of the hoist frame, enabling the use of a frame of comparatively small depth, which is thus available for conditions of low head room.

Assuming that anumber of loaded bodies are standing side by side on the platform 20, Fig. 3, and a truck A arrives with a loaded body B, my hoist may pick up a body B1 from any desired region of the platform, raise it higher than the other bodies and thus carry it into the position shown at B1 in Fig. 3; then the hoist may be attached to the freshly arrived loaded body B and that body raised into the position indicated by broken lines B2, in Fig. 3. This same operation will lower the body B1, and it may thus be deposited on a waiting truck Al, as indicated by the dotted lines B3, or it may be supported and the crane manipulated back toward the platform to carry the body B1 over the truck A, beyond which it may then be deposited. The system of dispatching the body by means of my hoist is quite flexible and may be varied according to trafiic conditions.

I claim 1. In a hoist of the character described, the. combination of a screw and nut couple, one of which is rotatable and the other of which moves longitudinally consequent upon such rotation, cables attached to the longitudinally movable member and passing in opposite directions therefrom, sheaves about which such cables pass laterally, and other sheaves about which they pass downwardly, whereby depending cable-reaches are provided for acting on two independent loads to raise one while the other is lowered.

2. In a hoist of the character described, the combination of a frame, a centrally mounted horizontal screw therein, means for rotating the screw, a nut on the screw, a member parallel with the screw serving a guide the nut while preventing its rotation, a cable attached to the nut and leading in one direction therefrom parallel with the screw, thence about a sheave and adapted to be eventually connectcd to a load in a region at 'one side of the screw, and a cable attached to the nut and leading in the opposite direction therefrom and about a sheave and eventually connected to a load in a region on the other side of the screw.

3. In a hoist, the combination of a frame, a centrally placed horizontal screw extending transversely of the frame, a transverse guide parallel with the screw, a nut on the screw engaging the guide, a set of four cables attached to the nut extending parallel therewith to about the end of the screw and then guided laterally and backwardly and downwardly to depend at the four corners of a rectangle on 'one side of the screw, a second set of four cables attached to the nut and leading in the opposite direction parallel with the screw to about the other end of it and then guided laterally and backwardly in the direction opposite to the first-mentioned set of cables and thence downwardly at four corners of a rectangle at the opposite side of the screw from the first mentioned four corners.

4. In a hoist, the combination of a frame, a screw journalled therein, a nut on the screw, load raising members leading in opposite directions from the nut and adapted to be connected to different loads, thrust hearings on opposite ends of the screw, each arranged to resist longitudinal movement thereof only in the pulling direction, and means for rotating the screw.

5. In a hoist of the character described, the combination of a frame, cylindrical bearings carried thereby, a screw journalled in said bearings, means for rotating the screw, thrust bearings at the opposite ends of the screw, each adapted to resist longitudinal movement thereof only in the pulling direction, a suitably guided traveling nut on the screw, and load raising mechanismsconnected to the nut and exerting opposing stresses thereon.

6. In a hoist of the character described, the combination of a frame, a horizontal screw journalled therein, means carried by the frame for rotating the screw, cylindrical hearings on the frame for supporting the screw, thrust bearingsat the opposite ends of the screw, each adapted to resist longitudinal movement of the screw only in the direction from that end toward the other end, a suitably guided traveling nut on the screw, and a pair of cables connected to the nut and leading in opposite directions therefrom and around sheaves and eventually depending to two independent loads.

7..In a hoist of the character described, the combination of a frame, a screw carried thereby, thrust bearings at the opposite ends of the screw each comprising a head on the screw and an annular member carried by the frame and loosely surrounding the screw on the inner side of the head, whereby only one of the bearings may resist thrust at any given time, a traveling nut on the screw, and hoisting mechanism connected to the nut and adapted to exert opposing stresses thereon.

8. In a hoist of the character described, the combination of a frame, a horizontal screw journalled therein, means for rotating the screw, thrust bearings at the opposite ends of the screw, each adapted to resist lon- 'tudinal movement thereof only in the pullmg direction, rollers in the respective thrust bearings, suitable cages to hold the rollers in position with their race members when the pressure is relieved on that bearing, a suitably guided traveling nut on the screw and hoisting mechanism connected to the nut and adapted to exert opposing stresses thereon.

9. In a hoist of the character described, the combination of a frame, a horizontal screw rotatably carried by the frame, means for rotating the screw, thrust bearings at the opposite ends of the screw, each adapted to resist longitudinal movement thereof only in the pulling direction, a suitably guided traveling nut on the screw, four cables leading from the nut parallel with the screw, thence about sheaves so that two of the cables turn hackwardly parallel with the screw and near to it and the other two turn backwa-rdly from the screw but a considerable distance from i it, such four cables then dependingsover four sheaves spaced at the four corners of a rectangle on one side of the screw, and another set of four cables anchored to the nut and passing in the opposite directions from those specified and about the sheaves and depending at the four corners of an equal rectan le on the other side of the screw.

10. n a hoist, the combination of a frame, ascrew and nut couple carried thereby, means for rotating one member of the couple with reference to the other to cause the nut to travel, cables suitably connected with the nut and leading in opposite directions therefrom and adapted to be connected to different loads, and oppositely acting thrust hearings on opposite ends of the screw, each arranged to resist a longitudinal stress on the screw only in the pulling direction.

11. In a hoist of the character described, the combination of a screw and nut couple, one of which is rotated and the other of which moves longitudinally consequent upon such rotation, and cables connected with the longitudinally movable member and passing in op- 85 posite directions therefrom, substantially parallel with the path of travel of the movable member, whereby said movement tautens one cable and slackens the other, means for guiding the respective cables laterally in opposite directions, and sheaves over which the laterally guided cables depend.

12. In a hoist of the character described, the combination of a frame, a rotatable screw therein, a traveling nut on the screw, cables connected with the nut and extending in opposite directions therefrom, so that one cable is tautened and the other slackened when the screw is rotated, means for guiding the cables laterally in opposite directions, and sheaves over which the laterally guided cables depend.

13. In a hoist of the character described, the combination of the screw and nut couple, one of which is rotatable and the other of which moves longitudinally consequent upon such rotation, two sets of four cables each, each set being connected to the longitudinally movable member in such manner that when one set is tautened the other set is slackened and means for causing the four cables of each set to depend at the four corners of a rectangle, each of said depending cables being connected to load engaging means, whereby two demountable bodies may be engaged and either one raised while the other is lowered.

In testimony whereof, I hereunto affix my 

